(a + b - c + d)2 - (a - b + c - d)2 = ?
Show answer & explanation
Correct answer: C
Explanation
The correct answer is Option 3 i.e 4a(b + d - c).
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Understanding/Application |
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A2 - B2 = (A + B) (A - B) A = (a + b - c + d) and B = (a - b + c - d) |
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(A + B) (A - B) = {(a + b - c + d) + (a - b + c - d)} {(a + b - c + d) - (a - b + c - d)} = (a + a + b - b - c + c + d - d) (a - a + b + b - c - c + d + d) = 2a (2b - 2c + 2d) = 4a(b + d - c) |